1. Field of the Invention
The present invention relates to movable body systems, movable body drive methods, pattern formation apparatus, pattern formation methods, exposure apparatus, exposure methods, and device manufacturing methods, and more particularly to a movable body system including a movable body which substantially moves along a predetermined plane, a movable body drive method to drive the movable body, a pattern formation apparatus equipped with the movable body system, a pattern formation method which uses the movable body drive method, an exposure apparatus equipped with the movable body system, an exposure method which uses the movable body drive method, and a device manufacturing method which uses the exposure apparatus or the exposure method.
2. Description of the Background Art
Conventionally, in a lithography process for manufacturing electron devices (microdevices) such as semiconductor devices (such as integrated circuits) and liquid crystal display devices, exposure apparatuses such as a projection exposure apparatus by a step-and-repeat method (a so-called stepper), or a projection exposure apparatus by a step-and-scan method (a so-called scanning stepper (which is also called a scanner) is mainly used.
Semiconductor devices will lead to higher integration in the future, and accompanying this, it is certain that the circuit pattern which should be formed on the wafer will be finer, and further improvement of the position detection precision of wafers and the like will be required in the exposure apparatus which is the mass-production apparatus for semiconductor devices.
For example, in U.S. Patent Application Publication No. 2006/0227309, an exposure apparatus is disclosed which employs an encoder type sensor (an encoder head) installed on a substrate table. However, in the case when an encoder head is installed on a substrate table, the movement of the substrate table (acceleration added to the substrate table) could change the setting position and/or setting attitude of the encoder head with respect to the substrate table, and there was a risk of the accuracy of position measurement of the substrate table using the encoder head being degraded.